<SUBMISSION>
<ACCESSION-NUMBER>0000891836-00-000736
<TYPE>SC TO-T/A
<PUBLIC-DOCUMENT-COUNT>1
<FILING-DATE>20001213
<GROUP-MEMBERS>KONINKLIJKE PHILIPS ELECTRONICS NV
<GROUP-MEMBERS>PHILIPS HOLDING USA INC.
<GROUP-MEMBERS>PHILIPS MEDICAL ACQUISITION CORPORATION
<SUBJECT-COMPANY>
<COMPANY-DATA>
<CONFORMED-NAME>ADAC LABORATORIES
<CIK>0000313798
<ASSIGNED-SIC>3844
<IRS-NUMBER>941725806
<STATE-OF-INCORPORATION>CA
<FISCAL-YEAR-END>0930
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>SC TO-T/A
<ACT>34
<FILE-NUMBER>005-32403
<FILM-NUMBER>788002
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>540 ALDER DR
<CITY>MILPITAS
<STATE>CA
<ZIP>95035
<PHONE>4083219100
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>540 ALDER DR
<CITY>MILPITAS
<STATE>CA
<ZIP>95035
</MAIL-ADDRESS>
</SUBJECT-COMPANY>
<FILED-BY>
<COMPANY-DATA>
<CONFORMED-NAME>KONINKLIJKE PHILIPS ELECTRONICS NV
<CIK>0000313216
<ASSIGNED-SIC>3600
<STATE-OF-INCORPORATION>P7
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>SC TO-T/A
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>REMBRANDT TOWER AMSTELPLEIN 1
<STREET2>1096 HA AMSTERDAM
<CITY>THE NETHERLANDS
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>REMBRANDT TOWER AMSTELPLEIN 1
<STREET2>1096 HA AMSTERDAM
<CITY>THE NETHERLANDS
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>PHILIPS ELECTRONICS N V
<DATE-CHANGED>19930727
</FORMER-COMPANY>
</FILED-BY>
<DOCUMENT>
<TYPE>SC TO-T/A
<SEQUENCE>1
<FILENAME>0001.htm
<DESCRIPTION>SCHEDULE TO, AMENDMENT NO. 6
<TEXT>

<HTML>
<HEAD>
<TITLE>
SCHEDULE TO, AMENDMENT NO. 6
</TITLE>
</HEAD>
<BODY>

<P ALIGN=CENTER>
<FONT SIZE=-1><B>As filed with the Securities and Exchange Commission on
December 12, 2000</B></FONT>
</P>

<TABLE WIDTH=30%  ALIGN=RIGHT CELLPADDING=2 CELLSPACING=0 BORDER=2>
<TR>
     <TD ALIGN=CENTER>
     <B><FONT SIZE=-1>OMB APPROVAL</FONT></B>
     </TD>
</TR>
<TR>
     <TD>
     <B><FONT SIZE=-1>OMB Number: 3235-0515</FONT></B>
     </TD>
</TR>
<TR>
     <TD>
     <B><FONT SIZE=-1>Expires: January 31, 2002</FONT></B>
     </TD>
</TR>
<TR>
     <TD>
     <B><FONT SIZE=-1>Estimated average burden <BR>
     hours per response: 43.5</FONT></B>
     </TD>
</TR>
</TABLE>

<BR><BR><BR><BR><BR><BR><BR><BR>

<P ALIGN=CENTER>
<B><FONT SIZE=+1>UNITED STATES<BR>
SECURITIES AND EXCHANGE COMMISSION</FONT><BR>
Washington, D.C. 20549</B>
</P>

<P ALIGN=CENTER>
<FONT SIZE=+1><B>Schedule TO</B></FONT>
</P>

<P ALIGN=CENTER>
<B>Tender Offer Statement under Section 14(d)(1) or 13(e)(1)<BR>
of the Securities Exchange Act of 1934</B>
</P>

<P ALIGN=CENTER>
<B>(Amendment No. 6)</B>
</P>

<P ALIGN=CENTER>
<B>ADAC Laboratories<BR>
<BR>
<FONT SIZE=-2>(Name of Subject Company (Issuer))</FONT></B>
</P>

<P ALIGN=CENTER>
<B>Philips Medical Acquisition Corporation<BR>
<BR>
a Wholly Owned Subsidiary of<BR>
<BR>
Philips Holding USA Inc.<BR>
<BR>
a Wholly Owned Subsidiary of<BR>
<BR>
Koninklijke Philips Electronics N.V.<BR>
<BR>
<FONT SIZE=-2>(Names of Filing Persons)</FONT></B>

<P ALIGN=CENTER>
<B>COMMON STOCK,<BR>
NO PAR VALUE<BR>
<BR>
<FONT SIZE=-2>(Title of Class of Securities)</FONT></B>
</P>

<P ALIGN=CENTER>
<B><FONT SIZE=-2>005313200<BR>
<BR>
(CUSIP Number of Class of Securities)</FONT></B>
</P>

<P ALIGN=CENTER>
<B><FONT SIZE=-2>William E. Curran<BR>
<BR>
President<BR>
<BR>
Philips Holding USA Inc.<BR>
<BR>
1251 Avenue of the Americas<BR>
<BR>
New York, New York 10020</FONT></B>
</P>

<P ALIGN=CENTER>
<B><FONT SIZE=-2>(Name, address, and telephone numbers of person authorized<BR>
to receive notices and communications on behalf of filing persons)</FONT></B>
</P>

<P ALIGN=CENTER>
<FONT SIZE=-1>with a copy to:</FONT>
</P>

<P ALIGN=CENTER>
<B><FONT SIZE=-1>Matthew G. Hurd<BR>
Sullivan &amp; Cromwell<BR>
125 Broad Street<BR>
New York, New York 10004-2498<BR>
(212) 558-4000</FONT></B>
</P>

<P>&nbsp;</P>
<P>&nbsp;</P>
<HR NOSHADE SIZE=4>
<PAGE>

<P>&nbsp;</P>

<P>&nbsp;</P>

<HR SIZE=1 NOSHADE>

<TABLE WIDTH=100% CELLPADDING=0 CELLSPACING=0 BORDER=0>
<TR>
     <TH COLSPAN=2>CALCULATION OF FILING FEE</TH>
</TR>
<TR>
     <TD WIDTH=50%>&nbsp;</TD>
     <TD WIDTH=50%>&nbsp;</TD>
</TR>
<TR>
     <TD ALIGN=CENTER>Transaction valuation <SUP>(1)</SUP></TD>
     <TD ALIGN=CENTER>Amount of filing fee<SUP>(2)</SUP></TD>
</TR>
<TR>
     <TD ALIGN=CENTER>$489,852,842</TD>
     <TD ALIGN=CENTER>$97,971</TD>
</TR>
</TABLE>

<HR SIZE=1 NOSHADE>

<P>
(1)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Based on the offer to
purchase all of the outstanding shares of common stock of ADAC Laboratories
together with the associated rights to purchase Series A Junior Participating
Preferred Stock at a purchase price of $18.50 cash per share, 21,136,116 shares
outstanding and outstanding options with respect to 5,342,416 shares, in each
case as of November 12, 2000.
</P>
<P>
(2)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1% of 1/50<SUP>th</SUP>
of the transaction valuation.
</P>

<P>
[X]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Check the box if any
part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing
with which the offsetting fee was previously paid. Identify the previous filing
by registration statement number, or the Form or Schedule and the date of its
filing.<BR> Amount Previously Paid: $97,971<BR> Form or Registration No.:
005-32403<BR> Filing Party: Koninklijke Philips Electronics N.V.<BR> Date Filed:
November 14, 2000
</P>

<P>
[_]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Check the box if the
filing relates solely to preliminary communications made before the commencement
of a tender offer.

<P>
Check the appropriate boxes below to designate any transactions to which the
statement relates:<BR>
[X]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;third-party tender
offer subject to Rule 14d-1.<BR>
[_]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;issuer tender offer
subject to Rule 13e-4.<BR>
[_]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;going-private
transaction subject to Rule 13e-3.<BR>
[_]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;amendment to Schedule
13D under Rule 13d-2.

<P>
Check the following box if the filing is a final amendment reporting the results
of the tender offer:&nbsp;&nbsp;&nbsp;[_]
</P>

<P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
This Amendment No. 6 ("Amendment No. 6") to Schedule TO amends and supplements
the Schedule TO filed with the Securities and Exchange Commission ("SEC") on
November 14, 2000 (the "Original Schedule TO"), as amended by Amendment No. 1,
Amendment No. 2, Amendment No. 3, Amendment No. 4 and Amendment No. 5 to the
Original Schedule TO (collectively, the "Schedule TO"), by Koninklijke Philips
Electronics N.V., Philips Holding USA Inc. and Philips Medical Acquisition
Corporation ("Merger Sub") relating to the tender offer (the "Offer") commenced
by Merger Sub, on November 14, 2000 to purchase all of the outstanding shares of
common stock, no par value, of ADAC Laboratories ("ADAC") together with the
associated rights to purchase Series A Junior Participating Preferred Stock of
ADAC, no par value, at a price of $18.50 per share, net to the sellers in cash,
upon the terms and subject to the conditions set forth in the Offer to Purchase,
dated November 14, 2000, and the related Letter of Transmittal.
</P>

<P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
The information in the Schedule TO is hereby expressly incorporated herein by
reference in response to all the items of this Amendment No. 6, except as
otherwise set forth below. Capitalized terms used but not defined herein shall
have the meaning ascribed to them in the Original Schedule TO.
</P>

<P>&nbsp;</P>
<P ALIGN=CENTER>1</P>
<HR NOSHADE SIZE=4>
<PAGE>

<P>&nbsp;</P>
<P>&nbsp;</P>

<P>
<B>Item 5.&nbsp;&nbsp;&nbsp;Past Contacts, Transactions, Negotiations and
Agreements.</B>
</P>

<P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Item 5 of the Schedule TO is hereby amended and supplemented to include the
following sentences as the final sentences of each of the paragraphs captioned
"Employment" and "Employment Agreements" of Section 11 of the Offer to Purchase
entitled "Purpose of the Offer; Plans for the Company; the Merger":
</P>

<P>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Philips Electronics North America Corporation and Gerhard Burbach, the current
President and Chief Operating Officer of ADAC, have entered, as of December 3,
2000, into an employment agreement and a letter agreement relating to the
executive severance agreement between ADAC and Mr. Burback dated September 2,
1998. These agreements are incorporated by reference as Exhibits 99(a)12 and
99(a)13, respectively. Philips Electronics North America Corporation and Ian
Farmer, the current Senior Vice President Business Development of ADAC, have
entered, as of December 3, 2000, into an employment agreement and a letter
agreement relating to the executive severance agreement between ADAC and Mr.
Farmer dated September 2, 1998. These agreements are incorporated by reference
as Exhibits 99(a)14 and 99(a)15, respectively.
</P>

<P>
<B>Item 12.&nbsp;&nbsp;&nbsp;Exhibits.</B>
</P>

<P>
The following are attached as exhibits to this Schedule TO:
</P>

<TABLE WIDTH=100% CELLPADDING=0 CELLSPACING=0 BORDER=0>
<TR VALIGN=TOP>
<TD WIDTH=15%>99(a)(12)</TD>
<TD WIDTH=85%>      Employment Agreement Between Philips Electronics North
                    America Corporation and Gerhard Burbach, dated December 3,
                    2000 (incorporated herein by reference to Exhibit 12 of ADAC
                    Laboratories' Amendment No. 5 to its Schedule
                    14D-9).<BR><BR></TD>
</TR>

<TR VALIGN=TOP>
<TD WIDTH=15%>99(a)(13)</TD>
<TD WIDTH=85%>      Letter Agreement dated December 5, 2000, relating to the Executive
                    Severance Agreement dated September 2, 1998, between Philips
                    Electronics North America Corporation and Gerhard Burbach
                    (incorporated herein by reference to Exhibit 13 of ADAC
                    Laboratories' Amendment No. 5 to its Schedule
                    14D-9).<BR><BR></TD>
</TR>

<TR VALIGN=TOP>
<TD WIDTH=15%>99(a)(14)</TD>
<TD WIDTH=85%>      Employment Agreement Between Philips Electronics North
                    America Corporation and Ian Farmer, dated December 3, 2000
                    (incorporated herein by reference to Exhibit 14 of ADAC
                    Laboratories&#146; Amendment No. 6 to its Schedule
                    14D-9).<BR><BR></TD>
</TR>

<TR VALIGN=TOP>
<TD WIDTH=15%>99(a)(15)</TD>
<TD WIDTH=85%>      Letter Agreement dated December 5, 2000, relating to the Executive
                    Severance Agreement dated September 2, 1998, between Philips
                    Electronics North America Corporation and Ian Farmer
                    (incorporated herein by reference to Exhibit 15 of ADAC
                    Laboratories&#146; Amendment No. 6 to its Schedule
                    14D-9).<BR><BR></TD>
</TR>
</TABLE>

<P>&nbsp;</P>
<P ALIGN=CENTER>2</P>
<HR NOSHADE SIZE=4>
<PAGE>

<P>&nbsp;</P>
<P>&nbsp;</P>

<P ALIGN=CENTER>
<B>SIGNATURE</B>
</P>

<P>After due inquiry and to
the best of our knowledge and belief, we certify that the information set forth
in this statement is true, complete and correct. </P>

<P>Date: December 12, 2000</P>

<TABLE WIDTH=100% CELLPADDING=0 CELLSPACING=0 BORDER=0>
<TR>
     <TD WIDTH=45%> </TD>
     <TD WIDTH=55%> </TD>
</TR>
<TR>
     <TD>&nbsp;&nbsp;</TD>
     <TD>                        <B>PHILIPS MEDICAL ACQUISITION CORPORATION</B><BR>
<BR><BR>
                                 By: &nbsp;&nbsp;<U>/s/ Belinda W. Chew</U><BR>
                                 Name:&nbsp;&nbsp;Belinda W. Chew<BR>
                                 Title:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Vice President <BR><BR><BR></TD>
</TR>
<TR>
     <TD>&nbsp;&nbsp;</TD>
     <TD>                        <B>PHILIPS HOLDING USA INC.</B><BR>
<BR><BR>
                                 By: &nbsp;&nbsp;<U>/s/ Belinda W. Chew</U><BR>
                                 Name:&nbsp;&nbsp;Belinda W. Chew<BR>
                                 Title:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Senior Vice President <BR><BR><BR></TD>
</TR>
<TR>
     <TD>&nbsp;&nbsp;</TD>
     <TD>                        <B>KONINKLIJKE PHILIPS ELECTRONICS N.V.</B><BR>
<BR><BR>
                                 By: &nbsp;&nbsp;<U>/s/ Cor Boonstra</U><BR>
                                 Name:  &nbsp;&nbsp;Cor Boonstra<BR>
                                 Title: &nbsp;&nbsp;&nbsp;&nbsp;
                                        President, Chairman of the Board of Management<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                                        and the Group Management Committee<BR><BR><BR></TD>
</TR>
<TR>
     <TD>&nbsp;&nbsp;</TD>
     <TD>                        By: <U>/s/ Jan H.M. Hommen</U><BR>
                                 Name:  &nbsp;&nbsp;Jan H.M. Hommen<BR>
                                 Title: &nbsp;&nbsp;&nbsp;&nbsp;
                                        Executive Vice-President, Chief Financial<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                                        Officer, Member of the Board of Management<BR>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                                        and the Group Management Committee<BR><BR></TD>
</TR>
</TABLE>

<P>&nbsp;</P>
<P>&nbsp;</P>
<HR NOSHADE SIZE=4>
<PAGE>
<P>&nbsp;</P>
<P>&nbsp;</P>

<P ALIGN=CENTER>
EXHIBIT INDEX
</P>

<TABLE WIDTH=100% CELLPADDING=0 CELLSPACING=0 BORDER=0>
<TR VALIGN=BOTTOM>
<TD WIDTH=15%>EXHIBIT<BR>
              <U>NUMBER</U></TD>
<TD WIDTH=85%><U>EXHIBIT DESCRIPTION</U></TD>
</TR>

<TR VALIGN=BOTTOM>
<TD WIDTH=15%>&nbsp;</TD>
<TD WIDTH=85%>&nbsp;</TD>
</TR>


<TR VALIGN=TOP>
<TD WIDTH=15%>99(a)(12)</TD>
<TD WIDTH=85%>      Employment Agreement Between Philips Electronics North
                    America Corporation and Gerhard Burbach, dated December 3,
                    2000 (incorporated herein by reference to Exhibit 12 of ADAC
                    Laboratories' Amendment No. 5 to its Schedule
                    14D-9).<BR><BR></TD>
</TR>

<TR VALIGN=TOP>
<TD WIDTH=15%>99(a)(13)</TD>
<TD WIDTH=85%>      Letter Agreement dated December 5, 2000, relating to the Executive
                    Severance Agreement dated September 2, 1998, between Philips
                    Electronics North America Corporation and Gerhard Burbach
                    (incorporated herein by reference to Exhibit 13 of ADAC
                    Laboratories' Amendment No. 5 to its Schedule
                    14D-9).<BR><BR></TD>
</TR>

<TR VALIGN=TOP>
<TD WIDTH=15%>99(a)(14)</TD>
<TD WIDTH=85%>      Employment Agreement Between Philips Electronics North
                    America Corporation and Ian Farmer, dated December 3, 2000
                    (incorporated herein by reference to Exhibit 14 of ADAC
                    Laboratories&#146; Amendment No. 6 to its Schedule
                    14D-9).<BR><BR></TD>
</TR>

<TR VALIGN=TOP>
<TD WIDTH=15%>99(a)(15)</TD>
<TD WIDTH=85%>      Letter Agreement dated December 5, 2000, relating to the Executive
                    Severance Agreement dated September 2, 1998, between Philips
                    Electronics North America Corporation and Ian Farmer
                    (incorporated herein by reference to Exhibit 15 of ADAC
                    Laboratories&#146; Amendment No. 6 to its Schedule
                    14D-9).<BR><BR></TD>
</TR>
</TABLE>


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</HTML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
